Unit 4 Fractions and percentages 2 Work out a 12% of 46 b 23% of 150 c 47% of 700 d 124% of 90 3 a Increase 40 by 10%. b Increase 30 by 10%. c Increase 20 by 50%. d Increase 180 by 80%. e Increase £3000 by 5%. Q3 hint 100% + 10% = 110% = 1.1 1.1 × 40 = 4 a Decrease 70 by 10%. b Decrease 60 by 10%. c Decrease 90 by 20%. d Decrease 40 by 60%. e Decrease £1000 by 5%. Q4 hint 100% − 10% = 90% = 0.9 70 × 0.9 = 5 Finance / Real VAT is 20%. Add VAT to a £750 b £1200 c £32 6 Finance / Real a Find the simple interest when £1500 is invested for 1 year at 1.75%. b Find the simple interest when £10 000 is invested for 2 years at 1.75%. c Find the simple interest when £1.5 million is invested for 2 years at 3.75%. Q6b hint Simple interest for 2 years = 2 × simple interest for 1 year. 4 Extend 1 Real / Problem-solving Scotland has an area of 30 000 square miles. _ 16 of the area is woodland. _34 of the area of woodland is covered with pine trees. Work out the area of woodland covered with pine trees. 116 2 Reasoning There are 21 questions in a test on biology, chemistry and physics. There are 7 biology questions and 8 chemistry questions. a What fraction of the questions are on biology? b What percentage of the questions are on physics? 3 Reasoning / Finance Last year Sasha was paid £3400 for her weekend job. This year Sasha’s pay increased by 2%. How much pay does Sasha get this year? 4 Real / Problem-solving Cherry wants to buy a pair of designer jeans. In Jeans R Us the original price for the jeans was £120. Q4 strategy hint Show your This price has now been reduced by 25%. working for Jeans R Us and The original price for the same pair of jeans at Designer Designer Bargains separately. Bargains was £110 but has been reduced by 20%. At which shop would Cherry pay less for the jeans? 5 Millie is collecting small coins in a jar. She empties the jar and counts 120 coins. _25 are 1p coins. 25% are 2p coins. The rest are 5p coins. What percentage of the coins are 5p coins? Q5 strategy hint Work out the percentage of 1p coins first.